We joke about oil-leaking VWs. “VW’s don’t leak—they are marking their territory”. We’ve all heard such cute sayings. But—-
NO–VW engines are NOT supposed to leak. However–there are several factors which “allow” them to leak–such as—–
Older Engine Cases, which have some flaws where the two Halves mate, can leak–work performed over the years may have caused some imperfections to these mating surfaces, or, sealant may not have been applied evenly before mating the two Halves.
Flywheel Seals may not perfectly seal the end of the Engine Case where the Flywheel installs. And/or the Flywheel may have developed small grooves where it rides upon the Seal. Over the miles, tiny grooves wear at that point and allow seepages. There are cheaper quality Seals on the market, also, which do not perform well.
The Oil Drain Plate Gaskets these days are not as good as the originals. A lot of them are “thinner” or of inexacting materials–so, they may seep.
During the removal of the Drain Plate and Strainer, when removing the old Gaskets, we may inadvertently scrape a bit too diligently and score the Case where the Gasket is supposed to seal. Seepages can develop at these points.
The Drain Plates themselves become distorted where the Securing Nuts tighten against them. Heat aids in this pressure-distortion process. The next time you have the Plate removed, note that the holes may be a bit raised, on the side which goes against the Engine Case. They should be perfectly flat. I have tried using a hammer, carefully, to flatten these Raised Stud Holes. A good VW shop may be able to do a better job. Or, just obtain a better used Plate or a new one.
Using a 10mm end wrench or a 10mm socket on a 1/4th inch ratchet (no larger than a 1/4 inch ratchet!!!), GENTLY tighten each Drain Plate Nut–using the cross-pattern tightening procedure. You may find that each Nut is a tad “loose”.
The Securing Nuts for the Drain Plate originally were Acorn Nuts. The reason is this: the closed end of the Acorn Nut prevents Oil Seepage—the closed end contains any Oil which may have seeped around and down the Threads. If the Securing Nuts for your Drain Plate are open-ended Nuts, obtain the correct Acorn Nuts. Volkswagen parts houses stock the correct Acorn Nuts.
Next–the Seal in the Transmission for the Input Shaft may be worn. It can seep Transmission Oil into the Bell Housing which weeps from there onto the ground. If too much Tranny Oil is leaking, it can fling onto the Clutch Plate and cause slippage or chattering of the Clutch against the Flywheel.
Next in line for leaks are the two Axle Tube Boots. If they have developed age cracks, they can leak. They always contain some Oil. Remedy: replace the Axle Boots with high quality Boots (don’t purchase the cheap ones). Install them according to VW’s instructions.
Pushrod Tube Seals and Push Rod Tubes, themselves, can leak. First–the Tubes: Each Pushrod Tube should be installed with the seam facing up. Seams CAN leak. Also, with time, the Seals (one at either end of a Pushrod Tube) become hardened and can/will leak. The remedy is to remove (or to have a qualified VW Technician do the job) the Rocker Arms, pull the Pushrods, loosen the Cylinder Heads and remove the old Pushrod Tubes and Seals and to replace Tube and Seals with new parts. Then, the Cylinder Heads must be re-torqued and the Pushrods reinstalled and the Rocker Arms reinstalled and re-torqued.
OR– Spring-loaded Tubes with Seals can be obtained. These can be installed without loosening the Cylinder Heads. They will perform properly.
A common location for Oil Seepages can be the Valve Covers. Always purchase high quality Valve Cover Gaskets. The cheap ones will under-perform, for sure.
Clean the surfaces where the new Gaskets will reside. Be sure to remove ALL vestiges of former Gasket Material from the Valve Covers and from the Cylinder Head mating surfaces. I never have used Sealants for securing Valve Cover Gaskets to the Covers. Many VW owners do use Sealants—that’s fine. It just causes more work the next time the old Gaskets must be removed. (I don’t like more work!). I oil both sides of a new Gasket and rub the oil into the Gasket. I carefully position the Gasket into the Valve Cover and carefully position the Cover onto the Cylinder Head. Once I believe that I have the Cover properly positioned, I snap the Bail into place. Then, I use the end of a hammer’s wooden handle or the handle end of a large screwdriver to tap along the bottom edge of the Valve Cover. Almost every time, I find that the Cover will move a bit upwards, helping to assure a tight fit. This has worked in my favor for over 46 years.
Be sure that the Valve Cover Bail is not distorted. If the Bail is distorted and cannot be corrected—find a good used replacement or buy a new Bail. And, don’t use deformed or badly rusted Valve Covers.
A less frequent origin of Oil Leakage is the Oil Cooler. The Oil Cooler resides inside the Fan Shroud. It seals against the top of the Engine Case using two Round Seals and 3 nuts and their washers. Over time, the two Seals become heat-hardened and will crack. They may seep at first or, they may just give way and leak a stream of oil. Usually this Leakage can be seen when looking at the Engine while standing behind the Beetle. The Oil will flow towards you from beneath the Fan Shroud, towards the rear of the car, then down the driver’s side of the Engine and down the side near the Oil Pressure Switch.
Now–about these Oil Seepages–Oil “migrates”. Thus, Oil from an Axle Boot will “migrate” to the rear of the vehicle as the Beetle is driven. What you find at the rear of the car actually may have come from farther to the front of the vehicle. We cannot assume the source of a seepage.
One way for identifying a point of seepage is to carefully clean the bottom of the car–assiduously! Leave no Oil behind!
Locate a large piece of cardboard which will cover the floor where you usually park your Beetle. The cardboard must be large enough to cover all areas mentioned above.
Once all traces of Oil have been removed–take the Beetle for a drive. Drive a few miles to get the Engine hot and all sources of Oil moving.
Park the Beetle in its accustomed location and position the cardboard.
Leave the car over-night. Without removing the cardboard–examine any Oil Drips on the cardboard and trace them upwards as best you can. This often can aid when identifying sources of Oil Seepages.
Take preventative measures and hopefully you will have reduced, or eliminated, Oil Seepages.
Note: If you find pooling oil beneath your Beetle, do not delay in locating and remedying the problem!